Nissan Leaf 7 Module Pack Wiring Drawing w/ Sergio Relays

[Pat911]

Ahh, glued cells, that may be a problem unless you can dissolve it.

Any JBD BMS will do a very good job. They have the parameter settings available to top balance.

I'm unfamiliar with the Alltrax. Best Volt_Ampare comments. I will say that you should leave some room for regen if your cart has that feature. Regen can push battery voltage up if the cells are already at a high state of charge.

Cheers
Pat.

[Caleb_mock]

How does the BMS trigger a cutoff? If one cell is connected to the BMS but not the main power, will the BMS still function as required for a Pingeye setup?

In other words, can a 16S JBD be set up to run 14 or 15 cells in series using the Pingeye setup and top balance the complete set when the stray is starting to lose charge?

[Pat911]

You will need a BMS specific to the number of cells you are using. The orphan cell will just sit there on its own slowly self discharging.

There are some BMS's that can be configured for say 12S-17S as an example, but you still cannot connect the orphaned cell. You can only connect the number of cells you require for the maximum voltage you desire.

[Caleb_mock]

I think I have a solution.

What if I took the extra cells, wired up a 4S BMS, and made a 14.8V Battery for accessories? The cells are already configured as 2p each, so if I stick with the 15S plan I can break the bus bar and have 35AH at 14.8V.

[Volt_Ampere]

You can do that - good idea. You need a separate charger for that though.

[Caleb_mock]

Hmmm maybe two on board chargers with one 110 volt input? 🤔

And I checked the XCT48XXX Datasheet. It does have a 62 volt maximum. Do you still think it's the right call to do a 14s instead of a 15s? I intend to undercharge a little bit to extend the life of these cells, but I don't want to leave any performance on the table.

[Volt_Ampere]

If you undercharge enough, you can use 15S but I think I would go with 14S. That's what I run with my Leaf cells and I have great performance. I don't like to push things to their voltage limits. It's up to you on that one.
I don't go for onboard chargers - don't like to subject them to vibration. The ones I use don't look rugged enough to me. I would only use an onboard if I had the need to charge at places other than in my garage. I like having the extra space in the cart also.

[Caleb_mock]

I talked with Scottyb at CartsUnlimited. He suggested running it as a 14s, not for the controller, but so that I didn't fry the solenoid or motor. The idea of having a 12 volt onboard 70AH battery is growing on me, so I was leaning that way anyway.

It's a good thing that the Chinese New Year was going on, because I've changed my BMS order twice this week 🤦.

I'm going to go ahead and order the Alltrax controller and Solenoid. The build is going to be documented over in the E-Z-Go lithium forum if anyone is reading this and wants to follow. Thank you both for your help so far and thank you Pingeye and Sergio (is it possible to tag people)?